This application relates to endovascular grafting apparatus, system and method and devices for use therewith.
The state of the art is described in the background of the invention in U.S. Pat. No. 4,787,899.
In general, it is an object of the present invention to provide an endovascular grafting apparatus, system and method and devices for use therewith which overcome the disadvantages of the prior art apparatus, systems and devices.
Another object of the invention is to provide an apparatus and system of the above character which utilizes a pusher rod assembly which is constrained so that relatively great forces can be applied by the pusher rod assembly.
Another object of the invention is to provide an apparatus and system of the above character in which the capsule is flexible so that it can negotiate bends in the vessels of a patient.
Another object of the invention is to provide a grafting apparatus and system which utilizes a flexible capsule which can contain a graft with hook-like elements without any danger of the hook-like elements penetrating the capsule.
Another object of the invention is to provide an apparatus and system of the above character in which the graft automatically springs into an open or expanded position when it is released from the capsule.
Another object of the invention is to provide an apparatus, system and method of the above character in which a pushing force is applied to the distal extremity of the balloon for advancing a graft out of the capsule.
Another object of the invention is to provide an apparatus and system of the above character in which a fixed wire or an over-the-wire guide wire system can be used.
Another object of the invention is to provide an apparatus and system of the above character in which the graft can be compressed to a very small size in a flexible capsule.
Additional objects and features of the invention will appear in the following description in conjunction with the accompanying drawings.
Another feature of the present invention is a novel attachment system that comprises a sinusoidal wire frame and V-shaped lumen piercing members. The sinusoidal frame has two ends and alternating base apices and protruding apices. The protruding apices protrude outward and are mounted onto the graft to extend outward past the end of the graft. The base apices are oriented inside the lumen of the graft and points inward from the end of the graft. The portion of the wire frame connecting the protruding apices to the base apices are struts.
In one embodiment, the two ends of the wire frame are welded together to obtain circular continuity of the wire frame. In another embodiment, the wire frame has one additional protruding apex and the ends of the wire frame terminate in helices generally aligned with the base helices. The frame is mounted by overlapping the two ends of the wire including a pair of protruding apices adjacent the end. The wire frame is sewn to the body of the graft at various points over the entire wire frame. The lengths of the struts may be adjusted to stagger the apices so that the profile of the wire frame and the graft can be minimized to fit into a smaller delivery capsule.
In addition to the wire frame, the attachment system further includes a plurality of lumen piercing members affixed to the struts. The lumen piercing members are configured to protrude radially outward from the attachment system to engage the lumen wall of a blood vessel and secure the graft in place to prevent migration of the graft along the blood vessel. The lumen piercing member of one embodiment includes a wire arm that has an outwardly protruding hook constructed of stainless steel wire. The hooks are aligned with and welded to the struts of the wire frame.
Another embodiment of the lumen piercing members eliminates the need for welds to secure the lumen piercing members to the graft. Each lumen piercing member is bent into a V-shape and each have an apex and two arms that extend in a direction parallel to the struts of the wire frame. The arms terminate in radially outward protruding hooks that are configured to engage the wall of the vessel. The lumen piercing member is secured to the graft in close proximity to the wire frame and is responsive to the outward bias of the wire frame.
Another embodiment of the attachment system of the present invention configured for use in the iliac arteries in a bifurcated graft includes two sinusoidal wire frames that have alternating base apices and protruding apices. Each of the iliac wire frames have two end arms that extend longitudinally outward to engage the iliac artery wall. The wire arms are configured as lumen piercing members which extend as struts from the end base apices. The two wire frames are joined together by overlying the end base apex of one of the wire frames with the end base apex from the other wire frame such that each of the wire arms extend parallel to an adjacent strut. The end arms are twisted around the adjacent struts and bent behind the protruding strut that is integrally connected to the adjacent strut. The ends of the lumen piercing member is hook-like to securely engage the vessel wall. The hooks are secured to the vessel wall when an additional radially outward force presses the vessel into the lumen wall, such as from a deployment balloon.
Another feature of the present invention includes a device to substantially eliminate leaks around the perimeter of the graft at the ends where the attachment system engages the lumen wall. The outside of the graft is textured with a plurality of filaments or fibers that are spun, woven, knotted, pressed or otherwise loosely associated to form a puffed textured filler or tuft that is sewn to or affixed to the outside of the graft proximal to the end of the graft. The ends of the fibers may be frayed to increase the surface area of the tuft. Alternatively, strands of loosely spun synthetic yarn are cross-stitched around the perimeter of the graft proximate the attachment system.
Another feature of the present invention includes a graft that is crimped radially along at least a portion of the length of the graft. The crimps form a generally corrugated tubular surface defining a plurality of radially outwardly protruding ribs that are separated longitudinally by alternating inwardly directed folds or pleats. The crimping occurs along the length of the graft between the two attachment systems. The crimping may be configured over the entire length or over only a portion of the graft.
Other features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.